Grace Potter and the Nocturnals perform at GALApalooza at the Petrillo Band Shell in Grant Park Aug. 4, 2011.

Grace Potter and the Nocturnals perform at GALApalooza at the Petrillo Band Shell in Grant Park Aug. 4, 2011. (Darkroom Demons/Matt Reeves)

By Luis Gomez

"Saturday Night Live" cast member Jason Sudeikis took in "Southside of Heaven" at Second City Thursday. The "Horrible Bosses" and "Hall Pass" star did a little improv himself afterward.

David Arquette, "Twilight" star Kellan Lutz and Christopher Mintz-Plasse, aka "McLovin," hung out separately at the Underground Thursday. Mintz-Plasse was also spotted at Public House that night while Arquette was also spotted at Paris Club.

Danny and Chris Masterson hit Paris Club before heading to Sub 51 for Chris' DJ set.

"Lollapalooza" founder Perry Farrell dined at Japonais Thursday and stopped by the 5th annual GALApalooza party at the Petrillo Band Shell in Grant Park, where Grace Potter and the Nocturnals performed. Distrubed singer David Draiman also attended GALApalooza, which raised $243,000 for the Parkways Foundation.

TheNew York Yankees sightings continued at Roots Handmade Pizza Thursday. "Mr. October" Reggie Jackson stopped by the Ukrainian Village bar and restaurant after the Yanks win over the White Sox.

Muse bassist Chris Wolstenholme trained with the Fire Thursday on the Toyota Park practice field in Bridgeview and then dined with his bandmates at N9NE Steakhouse later that night. The band Ratatat also dined there that night.